<template>
  <div>
    <div class="todo-header">
      <input type="text" placeholder="请输入你的任务名称，按回车键确认" @keyup.enter="add" v-model="title"/>
    </div>
  </div>
</template>

<script>
import {nanoid} from 'nanoid'
export default {
  name:'TodoHeader',
  data(){
    return{
      title:''
    }
  },
  methods:{
    add(){
      //校验数据
      if(!this.title.trim())return alert('输入不能为空')
      // 将用户的输入包装为一个Todo对象
      const todoObj = {id:nanoid(),title:this.title,done:false}
      //通知App组件添加新的todo
      this.$emit('addTodo',todoObj)
      //清空输入
      this.title = ''
    }
  },
}
</script>

<style scoped>
  /*header*/
.todo-header input {
  width: 560px;
  height: 28px;
  font-size: 14px;
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 4px 7px;
}

.todo-header input:focus {
  outline: none;
  border-color: rgba(82, 168, 236, 0.8);
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.075), 0 0 8px rgba(82, 168, 236, 0.6);
}
</style>